Question

2 An alarm clock is kept inside a vessel as shown
in the figure. A person standing
close in
to it can distinctly hear the sound of alarm. (a) Does the sound become louder when
place the vessel about 1m away from him?
E himoting
Now, if the air inside the vessel is removed completely can he will be able to hear the
sound of alarm? (b) How will the loudness of alarm get affected when again the
yessel is about lm away from him​

Answer 1

Reason for not hearing the alarm when air is not in the vessel is because sound need to travel by a medium and if there is vaccum then sound cannot travel and we cannot here the sound.